Euclidian Distance

Let us assume that you want to compute the distance between two points: $A, B$. To do so, you can use the euclidean distance defined as

$d(B,A) =\sqrt{((B_1 - A_1)^2+(B_2 - A_2)^2)}$

You can generalize finding the distance between the two points $(A,B)$ to the distance between an $n$ dimensional vector as follows:

$d(\vec{v}, \vec{w}) = \sqrt{ \sum_{i=1}^{n} (v_i - w_i)^2}$

Here is an example where I calculate the distance between 2 vectors ($n = 3$).